Preheat the oven to 350°F. Place the ground beef in a large mixing bowl and add the onion, carrots, zucchini, bell pepper, and garlic.
Add the breadcrumbs, eggs, milk, Worcestershire sauce, salt, and black pepper to the bowl.
Mix everything together with your hands or a spoon until the ingredients are evenly combined but not overworked.
Shape the mixture into a 2-pound loaf and place it on a baking sheet or in a loaf pan.
Spread the ketchup evenly over the top of the loaf.
Bake for 60 minutes, or until the internal temperature reaches 160°F. Let the meatloaf rest for 10 minutes before slicing.